How strong is Descartes' system? (Philosophy HL)

The big idea: Descartes built a chain: doubt → the cogito → dualism → God → the world. A chain is only as strong as its weakest link.

So the real Paper-2 question isn't 'what did Descartes say?' — it's how much of it actually survives when you press on it.

Two objections do the most damage: the Cartesian circle aimed at the God-proofs, and the interaction problem aimed at dualism.

Hold onto this: Evaluating isn't just 'I disagree.' It's testing each link: is the reasoning valid, are the premises true, does the objection really bite?

The most famous objection targets the God-proofs at the heart of the rebuild.

Checkpoint — the circle: In one line: if God guarantees clear ideas but you needed clear ideas to prove God, the rebuild may rest on nothing. Hold that — it threatens everything after the cogito.

The second objection hits dualism, and then we can ask what's left standing.

How do mind and body touch?: If the mind is unextended (no location, no physical force) and the body is purely physical, how does one move the other? When you decide to raise your arm, a non-physical thought somehow pushes a physical muscle — but physical things are moved by physical causes. Princess Elisabeth of Bohemia put this to Descartes directly, and he never gave a satisfying answer. The very gap dualism opens between mind and body makes their obvious teamwork hard to explain.

Go further — higher-level insight: A top answer separates the foundations from the building. The cogito and the method of doubt are Descartes' lasting gifts and largely survive. It's the upper storeys — the God-proofs and the world they support — that critics knock down. Saying which parts fall and which stand is exactly the evaluation part (b) rewards.